describing-request-body.md

Describing Request Body

Request bodies are typically used with "create" and "update" operations (POST, PUT, PATCH). For example, when creating a resource using POST or PUT, the request body usually contains the representation of the resource to be created.

It's important to note that unlike parameters, request bodies are optional by default. To mark the body as required, use @bodyRequired.

/**
 * POST /pets
 * @summary Add a new pet
 * @bodyDescription Optional description in *Markdown*
 * @bodyContent {Pet} application/json
 * @bodyContent {Pet} application/xml
 * @bodyContent {PetForm} application/x-www-form-urlencoded
 * @bodyContent {string} text/plain
 * @bodyRequired
 * @response 201 - Created
 */

@bodyContent allows wildcard media types. For example, image/* represents all image types; */* represents all types and is functionally equivalent to application/octet-stream. Specific media types have preference over wildcard media types when interpreting the spec, for example, image/png > image/* > */*.

Note: */* must be escaped in comments with *\/*.

// Can be image/png, image/svg, image/gif, etc.
/**
 * PUT /avatar
 * @summary Upload an avatar
 * @bodyContent {binary} image/*
 * @bodyRequired
 * @response 201 - Created
 */

// Can be anything.
/**
 * PUT /file
 * @summary Upload any file
 * @bodyContent {binary} *\/*
 * @bodyRequired
 * @response 201 - Created
 */

Reusable request bodies

Request bodies can be defined in components to be reused elsewhere. The following request body definition:

components:
  requestBodies:
    PetBody:
      description: A JSON object containing pet information
      required: true
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Pet'

Can be reused as:

/**
 * POST /pets
 * @summary Add a new pet
 * @bodyComponent {PetBody}
 */

/**
 * PUT /pets/{petId}
 * @summary Update a pet
 * @bodyComponent {PetBody}
 */

Form data

The term "form data" is used for the media types application/x-www-form-urlencoded and multipart/form-data, which are commonly used to submit HTML forms.

• application/x-www-form-urlencoded is used to send simple ASCII text data as key=value pairs. The payload format is similar to query parameters.
• multipart/form-data allows submitting binary data as well as multiple media types in a single message (for example, image and JSON). Each form field has its own section in the payload with internal HTTP headers. multipart requests are commonly used for file uploads.

To illustrate form data, consider an HTML POST form:

<form action="http://example.com/survey" method="post">
  <input type="text"   name="name" />
  <input type="number" name="fav_number" />
  <input type="submit"/>
</form>

This form POSTs data to the form's endpoint:

POST /survey HTTP/1.1
Host: example.com
Content-Type: application/x-www-form-urlencoded
Content-Length: 28

name=Amy+Smith&fav_number=42

Form data is defined in components and modeled using a type: object schema where the object properties represent the form fields:

components:
  schemas:
    Survey:
      type: object
      properties:
        name:          # <!--- form field name
          type: string
        fav_number:    # <!--- form field name
          type: integer
      required:
        - name
        - fav_number

It can be used with:

/**
 * POST /survey
 * @bodyContent {Survey} application/x-www-form-urlencoded
 * @bodyRequired
 */